Embodiments herein generally relate to continuous media (“web”) processing systems, such as printers that use paper from continuous paper rolls, and more particularly to a processing system that adjusts the position of one of the rollers so that the critical resonance frequencies of the system are at different frequencies than one of the excitation frequencies produced by the processing system.
Good motion quality of direct marking systems using continuous paper web feeding is critical if high quality prints are to be produced. The overall motion quality is greatly affected by the paper/drive roll/idler roll system resonances, especially for the first several system resonance frequencies. A commonly accepted practice in good vibrations/motion quality engineering is to design systems to avoid all disturbance sources such as eccentricities from occurring at the system resonance frequencies. With photoreceptor (P/R) belt or intermediate transfer belt (ITB) systems, “tuning” the motion quality is a little easier since the belt material does not change and aligning system anti-resonances with system disturbances produced by shaft run-out or the like is typically unaffected significantly by changing paper weight. This principle, however, becomes very hard to enforce in continuous paper web systems since when paper weight is changed from one print job to the next, the stiffness between the roll inertias in the system changes and so does the system dynamic response, i.e., system resonance frequencies. The shift in resonance frequencies due to the change in media increases the range of frequencies the disturbance source needs to avoid and may create color registration or other motion quality related problems that even a dual reflex printing algorithm cannot accommodate.
One exemplary method herein comprises a process that provides one or more media characteristics of a continuous media material (such as printing media) being supplied to rollers of an apparatus (such as a printing apparatus). The method adjusts the position of at least one of the rollers, relative to other rollers, based on the media characteristics to cause the media material to exhibit a target resonance frequency when being processed through the rollers.
The method can also identify one or more excitation frequencies of vibrations produced by the apparatus as the apparatus feeds the continuous media material along the rollers and set the target resonance frequency at a value that is different from these excitation frequencies, to prevent the apparatus from exciting the continuous media material at a resonant frequency of the continuous media material. In some embodiments, this “target resonance frequency” is set at a value that is more than a predetermined frequency range outside the excitation frequencies so that the resonance frequency selected is well outside any potential excitation frequencies.
Thus, when the roll of media material is changed and a second continuous media material is supplied to the rollers of the apparatus, the method can then provide “second” media characteristics of the second continuous media material. The second continuous media material is different from the continuous media material, and the second media characteristics are different from the media characteristics. Given these second media characteristics, the method can then adjust the position of at least one of the rollers (based on the second media characteristics) to cause the processing system with the second media material to exhibit a critical resonance frequency when being processed through the rollers that is the same as (or within a predetermined frequency range of) the target critical resonance frequency.
An apparatus embodiment (which can potentially be a printing apparatus) includes rollers receiving a continuous media material (which can be a printing media material) from, for example, a supply roll. Further, a first component (such as sensors, a user interface, a network connection, etc.) is operatively connected to a controller. The first component can detect media characteristics of the continuous media material or the first component can be provided with such media characteristics of the continuous media material from the user, from a network, etc.
In turn, the first component provides the media characteristics of the continuous media material to the controller. An actuator is operatively connected to the controller and to at least one of the rollers. The actuator (under control of the controller) adjusts the position of at least one of the rollers (relative to other rollers) again based on the media characteristics, to cause the processing system to exhibit a target resonance frequency when being processed through the rollers.
The apparatus can also use a second component that is also operatively connected to the controller. Similar to first component above, the second component can comprise sensors, a user interface, a network connection, etc. The second component identifies one or more critical excitation frequencies of vibrations produced by the apparatus as the apparatus feeds the continuous media material along the rollers, and provides the excitation frequencies to the controller. The controller then sets the target critical resonance frequency at a value that is different from the excitation frequencies. Again, the target resonance frequency that is set by the controller can be at a value that is more than a predetermined frequency range outside the excitation frequencies so that the resonance frequency selected is well outside any potential excitation frequencies.
If the supply roll is changed to a different media material, the first component can provide second media characteristics of the second continuous media material being supplied to the rollers. In turn, the controller adjusts the position of at least one of the rollers (based on the second media characteristics) to cause the processing system with the second media material to exhibit a second resonance frequency when being processed through the rollers that is the same as (or within a predetermined frequency range of) the target resonance frequency.
These and other features are described in, or are apparent from, the following detailed description.